| 摘要 |
542,125. Preserving food. BARKER, J. March 15, 1940, No. 4836. [Class 49] Potatoes or other starchy vegetables are cooked, mashed or minced without previous cooling, allowed to stand for a "conditioning" period, and finally dried, the final product being a dry powder which may be reconstituted as mash by adding hot water. Before conditioning, the mass may be partly dried. The conditioning reduces or eliminates the tendency of the cooked mass to become sticky, and allows over-dried portions of the mass to take up water from damper material. The duration of conditioning depends ,among other things, on the temperature; the lower the temperature the shorter the conditioning period; if the conditioning temperature is low enough, the partial drying may be omitted. The conditioning temperature may be from 10‹C. to 20‹C. and the conditioning period from half an hour to 22 hours. When the conditioning results in freezing, the mass is thawed before drying. The conditioning period may be reduced, for example from 20 hours to 2 hours, by effecting the partial drying on a drum or roller drier; when a roller drier is used the semi-dry material may be removed by doctor knives, cooled, and compressed in to a closed container during the conditioning period to prevent evaporation. The conditioned or partly conditioned material may be passed through a brush sieve while being subjected to the action of hot dry air, the resulting powder being dried in a cabinet drier, a belt drier, a tower drier or a rotary drier. In an example, milk or butter is added to cooked mashed potatoes before conditioning. According to the Provisional Specification the process may be applied to fruit, and a substance (unspecified) which hastens retrogradation of starch or staling of bread may be used to accelerate the conditioning step. |
